| echinobothrium bonasum sp. n., a new cestode from the cownose ray, rhinoptera bonasus (mitchill 1815), in the western north atlantic. | echinobothrium bonasum sp. n. is described from the cownose ray, rhinoptera bonasus (mitchill), taken in atlantic coastal waters of chesapeake bay, virginia, and off sakonnet point, rhode island. this species can be distinguished from all others by the following combination of characters: 14 hooklets armature of 11 large hooks, six in the anterior row and five in the posterior row, flanked by 12 to 14 hooklets per side; 24 to 25 spines per row on the cephalic peduncle; 24 to 31 testes per segmen ... | 1980 | 7218100 |
| rhinoptericola megacantha gen. et sp. n., representing a new family of trypanorhynch cestodes from the cownose ray, rhinoptera bonasus (mitchill 1815). | | 1993 | 1195063 |
| pectoral fin locomotion in batoid fishes: undulation versus oscillation. | this study explores the dichotomy between undulatory (passing multiple waves down the fin or body) and oscillatory (flapping) locomotion by comparing the kinematics of pectoral fin locomotion in eight species of batoids (dasyatis americana, d. sabina, d. say, d. violacea, gymnura micrura, raja eglanteria, rhinobatos lentiginosus and rhinoptera bonasus) that differ in their swimming behavior, phylogenetic position and lifestyle. the goals of this study are to describe and compare the pectoral fin ... | 2001 | 11136623 |
| granulated peripolar epithelial cells in the renal corpuscle of marine elasmobranch fish. | granulated epithelial cells at the vascular pole of the renal corpuscle, peripolar cells, have been found in the kidneys of five species of elasmobranchs, the little skate (raja erinacea), the smooth dogfish shark (mustelus canis), the atlantic sharpnose shark (rhizoprionodon terraenovae), the scalloped hammerhead shark (sphyrna lewini), and the cow-nosed ray (rhinoptera bonasus). in a sixth elasmobranch, the spiny dogfish shark (squalus acanthias), the peripolar cells could not be identified am ... | 1989 | 2519933 |
| the presence of a juxtaglomerular apparatus in elasmobranch fish. | previous studies have concluded that a juxtaglomerular apparatus evolved in phylogenetic groups "higher" than elasmobranch fishes. the present study shows for the first time a distinct juxtaglomerular apparatus in four marine elasmobranchs, the spiny dogfish squalus acanthias), the smooth dogfish (mustelus canis), the little skate (raja erinacea), and the cownose ray (rhinoptera bonasus). serial semithin sections of these fishes' kidneys reveal the four morphological components of a juxtaglomeru ... | 1990 | 2268068 |
| organization of peripheral nerves and spinal roots of the atlantic stingray, dasyatis sabina. | 1. the sizes and numbers of axons in peripheral nerves and spinal roots were investigated in the stingray, dasyatis sabina. 2. the axons of the dorsal and ventral roots do not mingle in peripheral nerves of this animal as they do in higher vertebrates. thus, it was usually possible to split the peripheral nerve into two portions, one containing only dorsal root axons, the other containing only ventral root axons. this feature was useful for the analysis of certain aspects of spinal cord organiza ... | 1978 | 621549 |
| emendation of the generic diagnosis of tylocephalum (cestoda: lecanicephalidea: tetragonocephalidae), and description of tylocephalum brooksi n. sp. | a new species of tylocephalum is described from the spiral intestine of the cownose ray rhinoptera bonasus taken off venezuela. tylocephalum brooksi n. sp. is the third species described parasitizing this host species, along with t. pingue and t. bonasum. t. brooksi is similar to congeners in the possession of a scolex with a fungiform pars apicalis, craspedote segmentation, circummedullary vitellarium, external seminal vesicle, bilobed ovary, and medioventral uterus. however, this species diffe ... | 2000 | 11128485 |
| stability design and response to waves by batoids. | unsteady flows in the marine environment can affect the stability and locomotor costs of animals. for fish swimming at shallow depths, waves represent a form of unsteady flow. waves consist of cyclic oscillations, during which the water moves in circular or elliptical orbits. large gravity waves have the potential to displace fish both cyclically and in the direction of wave celerity for animals floating in the water column or holding station on the bottom. displacement of a fish can exceed its ... | 2015 | 26060212 |
| biomechanical model of batoid (skates and rays) pectoral fins predicts the influence of skeletal structure on fin kinematics: implications for bio-inspired design. | growing interest in the development of bio-inspired autonomous underwater vehicles (auvs) has motivated research in understanding the mechanisms behind the propulsion systems of marine animals. for example, the locomotive behavior of rays (batoidea) by movement of the pectoral fins is of particular interest due to their superior performance characteristics over contemporary auv propulsion systems. to better understand the mechanics of pectoral fin propulsion, this paper introduces a biomechanica ... | 2015 | 26079094 |
| differences in activity level between cownose rays (rhinoptera bonasus) and atlantic stingrays (dasyatis sabina) are related to differences in heart mass, hemoglobin concentration, and gill surface area. | aquatic animals are faced with the challenge of extracting oxygen from water, a medium that is metabolically expensive to ventilate and that contains just a fraction of the oxygen concentration relative to air, yet the physiologies of fishes have evolved to support a wide range of activity levels in nature. oxygen delivery components, including gill surface area (oxygen uptake), blood chemistry (oxygen transport), and the heart (system pump), have been positively correlated to activity level in ... | 2012 | 22395532 |
| visual fields of four batoid fishes: a comparative study. | the visual fields of elasmobranch fishes are not well characterized even though this is a fundamental element of the visual system. the batoid fishes (skates, rays) form a monophyletic clade within the subclass elasmobranchii and exhibit a broad range of morphologies and corresponding ecologies. we hypothesized that their visual field characteristics would reflect their diverse morphology and ecology. this was tested by quantifying the monocular, binocular and cyclopean horizontal and vertical v ... | 2008 | 18245624 |
| reprodution of the cownose ray, rhinoptera bonasus mitchill, 1815 (elasmobranchii, rhinopteridae), in captivity and newborn care. | | 2008 | 19197512 |
| a retrospective study of disease in elasmobranchs. | this report reviews diseases of 1546 elasmobranchs representing at least 60 species submitted to northwest zoopath from 1994 to 2010. cownose rays (rhinoptera bonasus) (78), southern rays (dasyatis americana) (75), dusky smooth-hounds (mustelus canis) (74), bonnethead sharks (sphyrna tiburo) (66), and bamboo sharks (hemiscylliidae) (56) were the most commonly submitted species. infectious/inflammatory disease was most common (33.5%) followed by nutritional (11.9%, mostly emaciation), traumatic ( ... | 2013 | 23528944 |